This research centers on the determination of the function of lens intrinsic membrane protein MP19 in both normal lens development and cataractogenesis. Abnormalities in MP19 expression may underlie some ocular pathologies such as cataract. The gene Lim2 that encodes MP19 is transcripted in a tissue- and developmental-specific manner indicating that it is highly regulated. The study of this Lim2 null mutation may provide insights into cataract formation. These animals should provide a useful genetic background on which to express other mutant Lim2 transgenes. Conventional techniques and strategies for cloning and analysis of nucleotide acid will be used to generate Lim2 targeting construct and screen both ES cell clones and chimaric mice. In addition, Lim2 knockout mice will be analyzed with integrated approaches in terms of physiological, biochemical, genetic, and morphological characteristics.